FIG. 30(1) is a sectional view showing a toner bottle 1 according to a first conventional art. FIG. 30(2) is a perspective view showing the toner bottle 1. The toner bottle 1 is formed into a substantially cylindrical form having a bottom, and is provided with a housing space 2 for containing toner. The toner bottle 1 is provided with a projection piece 5 protruding inward in the radial direction and extending spirally with an axis L1 as a center from one end portion 3 in the axial direction to the other end portion 4 in the axial direction. The other end portion 4 in the axial direction of the toner bottle 1 is provided an opening portion 6 in which a hole having a smaller inner diameter than that of the remaining portions is formed so that the housing space 2 is in communication with the space outside the toner bottle 1.
The toner bottle 1 is coupled to a main body of an image forming apparatus (not shown) such that the axis L1 is parallel with a horizontal direction by coupling the opening portion 6 to the toner supply port that is provided in the main body of the image forming apparatus. In this state, when the toner bottle 1 is rotated about the axis L1 by the drive force of the driving portion that is provided in the main body of the image forming apparatus, the toner contained in the housing space 2 is led to the opening portion 6 by the projection piece 5 and supplied to the toner supply port from the opening portion 6 (refer to, for example, Japanese Unexamined Patent Publication JP-A 07-020705(1995)).
FIG. 31 is a perspective view showing a developer supplying container 10 according to a second conventional art. The developer supplying container 10 is formed into a cylindrical form having closed opposite ends, and is provided with a housing space for containing toner. The developer supplying container 10 is provided with a first projection piece 13 protruding inward in the radial direction and extending spirally with an axis L10 as a center from one end portion 11 in the axial direction to a central portion 12 in the axial direction, and a second projection piece 15 protruding inward in the radial direction and extending spirally with the axis L10 as a center from the other end portion 14 in the axial direction to the central portion 12 in the axial direction. In the central portion 12 in the axial direction of the developer supplying container 10 is formed a through hole 16 that penetrates the container in the radial direction to communicate the housing space and the space outside the developer supplying container 10.
The developer supplying container 10 is coupled to the main body of the image forming apparatus (not show) such that the axis L10 is parallel with the horizontal direction and the central portion 12 in the axial direction is opened upward so as to face the toner supply port provided in the main body of the image forming apparatus. In this state, the developer supplying container 10 is rotated about the axis L10 by the drive force of the driving portion that is provided in the main body of the image forming apparatus. Accordingly, the toner contained in the housing space of the developer supplying container 10 is led to the central portion 12 in the axial direction by the projection pieces 13 and 15, and when the through hole 16 is disposed at the position facing the toner supply port, the toner is supplied to the toner supply port via the through hole 16 (refer to, for example, Japanese Unexamined Patent Publication JP-A 08-339115(1996)).
FIG. 32 is a perspective view showing conventional developer supplying containers 100 and 100A according to a third conventional art. On a circumferential surface of the container many body for containing the developer is spirally recessed a guide groove 101 for guiding the developer contained inside the container main body to the supply port, accompanied with the rotation of the container main body. On every one pitch of the spiral of these guide grooves 101 is provided a plurality of discontinuous portions 102 (refer to, for example, Japanese Unexamined Patent Publication JP-A 10-171227(1998)).
Since the above-described toner bottle 1 of the first conventional art shown in FIG. 30 and the above-described developer supplying container 10 of the second conventional art shown in FIG. 31 have projection pieces 5; 13 and 15 formed so as to extend along a spiral direction about an axis, the developer in the neighborhood of the projection pieces 5; 13 and 15 receive a pushing force in a conveying direction by coming into contact with the projection pieces 5; 13 and 15. This leads the coagulated developer in the neighborhood of the projection pieces 5; 13 and 15, to the supply port in a coagulated state, so that when being supplied in this state to the developing portion, there are risks that a rough particle of the developer is attached to a part of the recording paper, on which an image should be formed and that the developer is attached to a part of the recording paper, on which an image is not formed, that is called as a fog.
In addition, in cases of the first and second conventional arts, when a twisting force from the outside about the axis, a bending force from the outside and an impact are added, there is a danger that the toner bottle 1 and the developer supplying container 10 are easily damaged by the occurrence of cracks which extend substantially along the spiral direction in the projection pieces 5; 13 and 15. Moreover, in a developer supplying container 100 of the third conventional art, it is possible to avoid the above-described problems of the toner bottle of the first conventional art and the developer supplying container 10 of the second conventional art. However, a plurality of the discontinuous portions 102 are, as shown by a reference numeral 103, arranged on the same straight line or the same spiral orbit on the outer circumferential portion of the container main body and therefore, there is a problem that when the container main body receives a pushing force inward in a radial direction, the discontinuous portions 102 arranged on the same straight line or the same spiral orbit are compressed in a circumferential direction so as to be easily deformed.
Moreover, in the toner bottle 1 of the first conventional art and the developer supplying container 10 of the second conventional art, the projection pieces 5; 13 and 15 are formed so as to extend along the spiral direction about the axis and therefore, a conveying quantity of the developer becomes uniform with respect to the axial direction. In the case where the conveying quantity of the developer is thus uniform with respect to the axial direction, when the toner bottle 1 and the developer supplying container 10 are rotated, the developer contained in the toner bottle 1 and the developer supplying container 10 are uniformly conveyed to a discharge hole. Accordingly, there is a possibility that the conveyed developers are coagulated by being collided and pushed each other in the neighborhood of the opening portion 6 and the through hole 61.
In order to solve this problem, the inventors have devised a developer container comprising a container main body for containing the developer, formed into a cylindrical shape, having a discharge hole for discharging developer provided on a middle portion in the axial direction, the container main body conveying the contained developer to the discharge hole by being rotated about an axis thereof; and a supporting member for supporting the container main body from the outside in the radial direction all over the circumference, the container main body including at least the discharge hole from the outside in the radial direction all over the circumference so as to be freely rotated about an axis thereof, the supporting member having a leading through hole provided therein, the leading through hole guiding the developer discharged from the discharge hole of the container main body to the outside. A conventional configuration such that the developer is conveyed from one end portion in the axial direction of the container to the other end portion in the axial direction, involves a risk that a to-be-conveyed developer is coagulated by being pushed onto inside wall which is perpendicular to an axial line provided on the other end portion in the axial direction of the container. In the above-described developer container, it is possible to agitate the developer by mutual collision between the developer from the one end portion in the axial direction and the developer from the other end portion in the axial direction in the neighborhood of the discharge hole inside the container main body, that is on the middle portion in the axial direction where a wall surface perpendicular to the axial line seen in the conventional configuration is not provided. In this way, in comparison with the conventional container in which the discharge hole is provided on the other end portion of the container, the developer container in which the discharge hole is provided on the middle portion in the axial direction of the container main body has an advantage that the developer is hardly coagulated in the neighborhood of the discharge hole. However, in the developer container in which the discharge hole is provided on the middle portion in the axial direction of the container main body, in the case where the developer is coagulated at least either on the one end portion in the axial direction or the other end portion in the axial direction, it is necessary to soften the developer which is coagulated in approximately a half of the conveying distance in comparison with the conventional container in which the discharge hole is provided on the other end portion of the container. In the case of being unable to soften it, the developer is lead to the supply port in a state where the developer is coagulated. When the developer is supplied in this state, there are risks that a rough particle of the developer is attached to a part of the recording paper, on which an image should be formed and that the developer is attached to a part of the recording paper, on which an image is not formed, that is called as a fog.